Grain growers should keep a close eye out for pest infestations in grain stores after the difficult, wet harvest.

More problems are being reported and risk remains high, even in dried grain, due to mild temperatures and damp weather.

Storage pest consultant Ian Stott says most infestations can be found in surface layers of grain, so regular lancing and checking is required.

“Drying will only slow insect development – it won’t stop it,” he says. “In addition, this year grain has taken a long time to dry and this may have encouraged pest levels.

“Most beetles and weevils will thrive in grain at 14-15% moisture and will continue to develop at moistures approaching 10%. Mites don’t stop breeding until moistures drop below 12%.”

If a pest infestation occurs, the entire heap of grain will need to be moved and treated, as will any new storage area into which it is moved, says Mr Stott. He suggests Actellic 50EC at 8ml/t.

“At this time of year, insect kill could take up to a fortnight, depending on species and ambient conditions,” he says.

“It may also be prudent for those looking to try to gain value from their grain by storing through to the spring to move the grain anyway and properly condition it using the storage pesticide.”

He warns that using a handlance on a knapsack to treat the top layer of grain with Actellic is now banned.